Card clothing

ABSTRACT

Card clothing for flats comprising a plurality of elongated wire strips assembled in side by side relationship and inclined at an angle to the direction of fiber flow across the flats. The strips have upstanding portions laterally spaced apart, and each upstanding portion provides a row of teeth having sides inclined at an angle to the direction of fiber flow. Either the wire strips or conventional fillet card clothing can be covered to a predetermined extent with a plastic material to control or limit the degree of exposure of the teeth or pins.

Elite States Patent [191 Bechtel, Jr.

[111 3,793,677 [451 Feb. 26, 1974 CARD CLOTHING [75] Inventor: Alfred R. Bechtel, Jr., Portsmouth, 7

[73] Assignee: Ashworth Bros. Inc., Fall River,

Mass.

[22] Filed: July 29, 1971 [21] Appl. No.: 167,162

Related US. Application Data [63] Continuation-impart of Ser. No. 71,481, Sept. 11,

1970, Pat. No. 3,737,953.

[52] US. Cl. 19/113 [51] Int. Cl D0lg 115/26 [58] Field of Search 19/112, 113, 114, 97

[56] References Cited UNITED STATES PATENTS 693,817 2/1902 Mills et al. 19/113 1,688,418 10/1928 I-lancock..... 2,488,442 11/1949 Snape, Jr. 3,290,729 12/1966 Maynard 3,148,415 9/1964 Reiterer 19/113 FOREIGN PATENTS OR APPLICATIONS 1,067,137 l/1954 France 19/114 1,222,918 I/I96O France 19/113 758,506 10/1956 Great Britain... 934,118 8/1963 Great Britain 19/113 OTHER PUBLICATIONS Japanese Patent Publication (Fujii) No. 39-12863, Published 7-7-64.

Primary ExaminerDorsey Newton [5 7] ABSTRACT 4 Claims, 28 Drawing Figures PATENTED FEB 2 6 I974 sum 1 BF 7 INVENTOR ATTORNEYS Pmm miazsmu SHEET 3 BF 7 INVENTOR ALFRED R. BECHTEL,Jr.

M ,%%zyw V ATTORNEYS PATENIED FEB 2 61974 PATENTEDFEB26IS74 I 3,793,677

SHEET s 0? 7- v 'mvsuron ALFRED R. BECHTEL,Jr.

' ATTORNE Y3 PATENTEBFEBZBISM 5. sum s or U mvsuron ALFRED R; BECHTEL, Jr.

ATTORNEY! CARD CLOTHING CROSS REFERENCE TO RELATED APPLICATIONS This application is a continuation-in-part of my copending application Ser. No. 71,481, filed Sept. 11, 1970, now US. Pat. No. 3,737,953, entitled CARD CLOTHING.

BACKGROUND OF THE INVENTION 1. Field of the Invention This invention relates generally to apparatus for carding fibers and particularly to card clothing used on such apparatus.

2. Discussion of the Prior Art Conventional carding machines consisting of a rotating carding cylinder and a plurality of flat bars, commonly called flats, which surround about one-third of the surface of the carding cylinder. The surfaces of the carding cylinder and the flats are usually toothed or provided with upstanding wires, pins or needles so that the interaction of the carding cylinder and the flats open and combs the fibers and removes foreign matter therefrom. The result of the carding process is a clean, combed, uniformly dispersed sheet or web. The carding cylinder rotates, and typically the flats move also, in the same direction as the carding cylinder, but at quite different speeds. For example the carding cylinder normally has a peripheral surface speed in the magnitude of 2,20()5,000 feet per minute, while the flats move at a speed of about 4 to inches per minute. Only a few thousandths of an inch separate the teeth or pins of the carding cylinder from those of the flats. The great degree of relative motion between carding cylinder and flats causes a combing and teasing action in the fibers, resulting in the formation of the web.

Typically both carding cylinder and carding flat comprise a base upon which card clothing is mounted. Card clothing can be of the fillet type constructed of a heavy fabric through which pins or teeth are pushed, or it can be constructed of metallic elements having pins or teeth. Carding cylinders have been covered with wrappings of toothed metallic wire wound helically around the cylinder. Flats have generally been constructed using fillet card clothing utilizing flexible wire, but some have been covered with short strips of rigid metallic wire oriented parallel to the direction of fiber flow across the carding surface.

During the carding process, the carding surfaces set forth in the prior art have been known to load up, collecting and holding fibers, and quickly becoming ineffective for about 50 percent of the working cycle. This is caused by the arrangement of teeth or pins commonly used, which provides unswept open lanes between the rows of teeth or pins parallel to the direction of fiber flow, and which allows fibers to be pushed down to the base of the teeth or pins where they accumulate. Unopened and short fibers, known as 'flat strips, collected in the apparatus and had to be cleaned out and disposed of as waste. This normally results in a fiber loss of up at 4 percent in some cases, to which must be added the time and expense of shutting down and cleaning the machinery. Furthermore, prior art carding apparatus provides no means to control the currents of air that are created therein, and these currents of air can disturb the fiber flow through the apparatus, contributing to waste and ineffectiveness. It is also sometimes advantageous to provide a precise degree of exposure of the carding teeth or pins, a technique that is not easily achieved in prior art devices.

The prior art sets forth various methods and apparatus for providing carding surfaces which function more efficiently. However, these solutions to the above mentioned problems have consisted generally of adding complicated processes and equipment to the basic apparatus, and have not been satisfactory.

SUMMARY OF THE INVENTION This invention solves the problems set forth above. The novel carding surfaces disclosed herein are particularly well suited for use with flats. They are uncomplicated in theory and application, and result in carding machinery having high efficiency and a great deal of versatility.

In accordance with the teachings of this invention, a carding surface comprises a plurality of toothed strips arranged side by side such that the teeth are inclined at an angle to the direction of fiber flow across the carding surface. The toothed strips are advantageously in the form of strips of the metallic toothed wire often used as cylinder wire. In a preferred embodiment, each toothed strip is provided with a bend at a point intermediate the ends and a plurality of such toothed strips are nested together. The nest of toothed strips is oriented such that neither leg of the strips is parallel to the direction of fiber flow. It is also within the scope of the invention to form each toothed strip into a curved or arcuate configuration. This novel construction and orientation of toothed strips provides a random distribution of teeth over the carding surface, with no open lanes parallel to the direction of fiber flow into which unopened fibers and foreign matter can collect. Furthermore, the air flow through the carding machinery can be controlled by the orientation of the toothed strips, allowing optimum air flow characteristics for the particular machinery, speeds and fibers being utilized, and reducing the tendency of the apparatus to' blow out fibers or to choke with fibers. The web of fibers resulting from the use of this invention is of quality superior to that provided by prior art devices. The life of the cardi'ng surface is long and the efficiency of the carding process is very high.

The toothed strip set forth in this invention can be mounted on conventional flats by a variety of methods, making the invention adaptable to virtually any carding machine. For example, the metallic strips can be glued to the base of a groove cut in the flat, or welded to a metal cap or glued to a plastic cap which is molded to or fitted over the flat, or assembled in a throw-away" flat of inexpensive material which can be disposed of when the strips have deteriorated.

In another embodiment of the invention, the wire strips just described as well as fillet card clothing can be covered to a predetermined extent with a plastic material so that only a certain portion of the teeth protrude above the plastic, limiting the degree of exposure of the teeth. This is advantageous in situations where it is desired to expose the fibers to a small, rigid sharp tooth. Plastic material can, in like manner, be applied to the toothed wire used on other components of the carding machine such as the cylinder, lickerin, or doffer to limit the degree of tooth exposure.

The carding surface of this invention will not accumulate fibers or load up, since fibers cannot accumulate in lanes or at the base of the teeth or pins. Therefore, a clean working surface is presented at all times. The carding action is so complete that virtually all the fibers are completely opened, and there remain no unopened fibers which must be discarded as waste.

A measure of the advances by the instant invention is best seen in a comparison of the efficiency of carding machinery constructed in accordance with the invention with that of the prior art machines. Conventional carding machines operate with a total waste of between l r& and 4 percent, while carding machines using flats in accordance with this invention have total waste of less than l 1% percent waste. This is because the flat waste present in prior art machines varies between 1 b and 2 1% percent while in the instant invention there is virtually no flat waste.

It is an object of this invention to provide a new and novel carding surface which virtually eliminates waste due to loading, unopened fibers, and collection of foreign matter.

Another object of this invention is to provide a new and novel carding surface which controls air currents within the carding apparatus.

Another object of this invention is to provide a new and novel carding surface which can be applied to conventional movable carding flats.

Another object of this invention is to provide a new and novel carding surface which can be mounted on a flat in a variety of manners.

Another object of this invention is to provide a new and novel carding surface which limits the degree of exposure of each tooth or pin above a smooth surface.

Other objects and advantages of this invention will become apparent from a study of the attached drawings and the description of the preferred embodiments set forth below.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side elevation showing the general arrangement of elements in carding machines;

FIG. 2 is a perspective view of a strip of toothed metallic wire in accordance with the instant invention;

FIG. 3 is a plan view of a plurality of the strips of FIG. 3 mounted on a flat;

FIG. 4 is a sectional view taken through 4-4 of FIG.

FIG. 5 is an elevation, partially in section, of one manner of mounting the toothed strips upon a flat;

FIG. 6 is an elevation, partially in section, of another manner of mounting the toothed strips upon a flat;

FIG. 7 is an elevation, partially in section, of still another manner of mounting the toothed strips upon a flat;

FIG. 8 is an elevation, partially in section, of still another manner of mounting the toothed strips upon a flat;

FIG. 9 is an elevation, partially in section, of still another manner of mounting the toothed strips upon a flat;

FIG. 10 is an elevation, partially in section, of another embodiment of the invention;

FIG. 11 is a plan view of still another embodiment of the invention;

FIG. 12 is a plan view of still another embodiment of the invention;

FIG. 13 is a plan view of a carding surface in accordance with the teachings of the prior art;

FIG. 14 is a plan view of a basic embodiment of the invention;

FIG. 15 is a plan view of a succession of flats in accordance with the invention showing the air flow therethrough;

FIG. 16 is a plan view of another succession of flats in accordance with the invention showing the air flow therethrough;

FIG. 17 is a plan view of still another manner of mounting the toothed strips upon a flat;

FIG. 18 is an elevation, partially in cross-section, of the arrangement in FIG. 17;

FIG. 19 is a cross-section taken through l9--19 of FIG. 18;

FIG. 20 is an elevation, partially in cross-section, showing the relationship between the flat shown in FIGS. 17-19, and a carding cylinder;

FIG. 21 is a side elevation of a portion of the base plate of a disposable flat;

FIG. 22 is a section taken through line 22-22 of FIG. 21;

FIG. 23 is a perspective view of the end piece of a disposable flat;

FIG. 24 is a perspective view of a sprocket seat and chain-screw housing for use with a disposable flat;

FIG. 25 is a side view of the elements shown in FIG. 21-24 assembled into the end portion of a disposable flat;

FIG. 26 is an end elevation of FIG. 25;

FIG. 27 is an elevation, partially in section, of another embodiment of the invention showing plastic filled fillet card clothing on a flat; and

FIG. 28 is an elevation, partially in section, showing plastic filled fillet card clothing on a carding cylinder.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The process of carding textilefibers is accomplished by apparatus such as that pictured in FIG. 1. The carding process begins with a roll of fibers 10 from which an uncarded bat or web of fibers 12 is fed to a Iickerin 13. A plurality of teeth 14 on lickerin 13 engage the web 12. Interaction between teeth 14 on lickerin 13 and teeth 15 on carding cylinder 16, and the surface speed differential between liclcerin l3 and carding cylinder 16, resulting in the transfer of web 12 to carding cylinder 16. Surrounding about one-third of the periphery of carding cylinder 16 are a plurality of carding flats 17 carried by a flexible chain 18 and moving through a path delineated by guideways (not shown) approximating the shape of carding cylinder 16 and a plurality of guide wheels 19. The actual carding process is performed by the interaction between carding surfaces of carding cylinder 16 and movable flats 17. Both carding cylinder 16 and movable flats 17 move in the same direction. However, carding flats. 17 move in the magnitude of about 4-15 inches per minute while the surface speed of carding cylinder 16 can be about 2,200-5,000 feet per minute. These ranges are by way of illustration and not by limitation. Only a few thousandths of an inch separate the teeth points of the carding cylinder 16 and the movable flats 17. Once having been carded,

fibrous web 12 is removed from carding cylinder 16 by means of a doffer, not shown.

The teachings of this invention will be described generally in regard to the movable carding flats used in carding apparatus, although the teachings apply equally well to other types of flats and to carding cylinders.

The general concept of one aspect of this invention is best illustrated by a comparison of FIGS. 13 and 14. The prior art, illustrated by FIG. 13, includes flats in which the carding surface comprises rows of teeth separated by open lanes 21. It has been axiomatic in the prior art that these rows of teeth 20 be perfectly straight, and be aligned parallel to the direction of fiber flow. Fibers passing through lanes 21 are usually not opened and tend to collect therein. The air flow is controlled. It has been found, as now taught by the instant invention, that significantly better and more efficient carding can be obtained by aligning the rows of teeth 20 at an angle inclined to the direction of fiber flow, as shown in FIG. 14. In the arrangement of FIG. 14, the teeth 20 are randomly dispersed, exposing the entire spectrum of crossing fibers to the teeth, and lanes 21 are not parallel to fiber flow. Other embodiments of the invention, described below, offer certain additional advantages over the simple embodiment pictured in FIG. 14, but in general, the novel orientation of the rows'of teeth 20 with respect to the direction of fiber flow is basic to this aspect of the inventive concept.

More sophisticated embodiments of the invention offer additional advantages. Looking to FIG. 2, one basic element utilized in the invention is a toothed metallic wire strip 22, which has a base portion 23 and an upstanding portion providing rigid, triangular teeth 24. Base portion 23 can be of greater width than the toothed upstanding portion 24 to provide spacing between rows of teeth 24 when a plurality of strips 22 are assembled in side by side relationship to form a carding surface. Strip 22 is provided with a bend 25 at a point intermediate the ends. The use of bend 25 increases the randomization of teeth 24 without the excessive angularization that would be necessary to achieve the same result with a straight strip 22. Bend 25 also helps greatly in the assembling of a plurality of strips 22 into a carding surface for mounting on a flat, because by virtue of bend 25 strips 22 can be nested together and are thus much easier to handle and align. Again, in keeping with the basic premise of the invention, the plurality of toothed strips 22 are oriented in such a manner as to have one side of the teeth 24 presented at an angle inclined to the direction of fiber movement. As illustrated in FIG. 3, a plurality of bent strips 22 are assembled in side by side relationship upon a flat casting or base plate 26 having a receiving groove 27 and side sills 28. The direction of fiber movement is perpendicular to the longitudinal axis of the flat. Strips 22 are oriented so that legs 29 and 30, delineated by bend 25, are both at an angle inclined to the direction of fiber movement. In FIG. 3, both legs 29 and 30 are inclined at an angle A from the direction of fiber movement, and angles A are equal. However, these angles need not be equal, as later illustrated. FIG. 4 shows the side by side relationship of adjacent strips 22, which are shown glued into place by a glue 31.

FIGS. 5-10 show alternative methods of mounting I toothed sections 22 upon a flat casting. For example,

In FIG. 6, a toothed strip 22 is glued into place in a groove 37 milled in the surface of a hard pressed paper backing 39. Strips 22 are held in place by glue 49, and backing 39 is clamped to flat casting 26 by clamps 42 engaging notches 43 cut into backing 39.

The toothed strips 22 in FIG. 7 are glued to a backing 44 by glue 45 in a manner like those of FIG. 6. The backing 44 is then attached to flat casting 26 by means of glue 46.

The assemblage shown in FIG. 8 consists of plurality of toothed strips 22 mounted upon a molding backing 47 which has a receiving groove 48 and a hooked flange 49. Backing 47 can be molded on the casting 26 or can be molded separately and slid onto or snapped over flat casting 26. Strips 22 can be glued to backing 47, or can be pressed into backing 47 as it is being molded. Alternatively, the backing 47 may be extruded. Moreover, one of the hooked flanges may be eliminated on the trailing edge of the flat. Thus, the one flange 49 along the leading edge and the glued connection between the base plate and the backing 47 retains its snug relation to the base plate. The leading edge is that edge of the flat that faces into the direction of fiber flow, and thus is the edge first encountered by the fibers.

In FIG. 9 strips 22 are glued to the upper surface of backing 50. Also glued to backing 50 are two sill strips 51. Backing 50 is then glued to casting 26.

The embodiments of the invention pictured in FIGS. 10, 27 and 8 are particularly advantageous when it is desirable to limit the degree of exposure of each of the teeth. This is particularly advantageous when carding fibers to be used in making non-woven webs. In the embodiments of FIG. 10, a groove 52 is provided in the upper surface of a backing 53 which is in turn attached to the flat casting 26 by means such as a glue 54. A plurality of toothed strips 22 are positioned in groove 52 and are glued therein such that only a predetermined portion of each tooth 24 extends above the upper surface 55 of backing 53. A suitable plastic filling material 56 is then applied over the strips 22 level with surface 55 to cover the valleys between the teeth to any desired depth on the teeth between the valleys andthe points to leave only the tips of the teeth protruding above the plastic material. While any suitable plastic filling material may be used, resinous materials such as epoxy resins or polyester resins are particularly advantageous. The result is a smooth surface broken only by the protruding portions of teeth 24. The advantages of the basic teachings of the invention are preserved. In the same manner, plastic material may be applied to metallic wire teeth wound in the conventional helical manner around the cylinder, doffer or lickerin to cover the base of the wire and the valleys between the teeth to any desired depth on the teeth.

While the embodiment of FIG. 10 is directed to strips of toothed metallic wire, the plastic filling material aspect of the invention is also well suited for use in connection with conventional fillet card clothing. For example, a carding flat is shown in FIG. 27 comprised of a flat casting base plate 26 upon which fillet card clothing 101 is mounted. The card clothing is comprised of a conventional fabric backing 102 from which a plurality of pins 103 embedded therein extend upwardly. The pins 103 may be either straight as shown in the drawings or bent at a point midway between their ends. The card clothing 101 may be attached to flat casting 26 by clamps 104 on each edge thereof. It is to be understood that the card clothing may be attached to the flat casing 26 by any suitable means such as adhesive or by being positioned in a groove as shown in FIGS. 3 through 10 in connection with the strips of toothed metallic wire.

A suitable plastic filling material such as an epoxy or polyester resin is applied over the pins 103 to cover the backing 102 and the pins to a predetermined height such that essentially only the tips of the pins protrude above the smooth surface 106 formed by the plastic filling material. This has the advantage of not only limiting the degree of exposure of the pins 103 but also making the flexible pins rigid to provide the desired carding action.

The plastic filling material can also'be used on fillet card clothing mounted on other components of the carding machine such as the cylinder, lickerin, or doffer to limit the degree of pin or tooth exposure. For example, as shown in FIG. 28, the fillet card clothing 101 is shown mounted on a base 107 of a carding cylinder 16 by any suitable means such as an adhesive material wherein the pins 103, embedded in a backing 102 and protruding therefrom, are covered to a predetermined extent by plastic filling material 105.

Filling the space between the teeth or pins of either toothed metallic wire or conventional fillet card clothing with a hard, smooth surface material such as plastic precludes the possibility of stock becoming lodged between the teeth and having to be stripped out. By adjusting the depth of this filling to a level at which only a small part of the teeth or pins protrude, the carding action can be changed from straight carding and parallelization, with its attendant removal of short and immature fibers, to one of simple randomization with no stock removal. Additionally, with respect to the fillet card clothing, there is the advantage that the short protrusions of the pins are held rigidly by the hard plastic filler material and consequently are not subject to hairing up, which is a common occurrence with conventional card clothing.

Within the concept of presenting teeth 24 at an angle inclined to the direction of fiber flow, many configurations of strips 22 are possible. In FIG. 3, strips 22 have a bend 25 at the midpoint, and are oriented with regard to the direction of fiber such that two equal angles A are established with respect to the longitudinal axis of the flat 27. FIG. 11, however, shows two unequal angles B and C, and legs 60 and 61 thus present their respective teeth 24 at different angles to the direction of fiber flow.

In FIG. 12, toothed strips 22 have been formed into arcuate sections mounted with respect to the direction of fiber flow in such a manner that each tooth 24 presents an angle to the'direction of fiber flow. Although shown as a continuous equal radius of curvature, identically disposed on either side of the longitudinal axis of the flat, strips 22 can be of other curvilinear configuration within the inventive concept.

The invention is also capable of controlling the air currents within the apparatus without additional elements and complicated structure. FIGS. and 16 show two arrangements of a succession of flats 26a, 26b, 26c, and 26d, upon each of which a plurality of toothed strips 22 have been arranged in patterns to illustrate how the air flow through the flats can be controlled. In FIGS. 15, strips 22 are constructed accord ing to FIG. 3, that is, they are provided with a bend at a point intermediate the ends. The strips 22 on all the flats 260-260, are faced with their bends in the same direction. The flow of air, shown by the arrows, is divided into streams between each pair of adjacent strips 22, and owing to the arrangement of strips 22 upon successive flats, these air streams are caused to move from left to right, as illustrated. In contrast, FIG. 16 illustrates an arrangement where the sections 22 are faced in opposite directions on adjacent flats 26a, 26b, 26c, and 26d. The result of this arrangement, as shown by the arrows inFIG. 16, is to keep the flow of air entirely within the flats 26a26b, changing directions slightly as it crosses each flat, but never being directed to the outer edge of the flat. The latter arrangement is usually advantageous because the retention of the air flow Within the toothed portion of the flat prevents migration of loose fibers to the edge thereby minimizing waste. These two examples by no means show the full range of air control available by the use of this invention. Obviously, many other flow patterns can be achieved, dependent only upon the configuration and pattern of strips 22 used and their arrangement of successive flats.

Set forth in FIGS. 17-20 is another embodiment of the invention which is particularly advantageous when the movable flats are being used in conjunction with a carding cylinder. The more contact between the carding surface of the flats and the carding surface of the cylinder, the more efficient the carding process. In the devices advanced by the prior art, the carding flat usually presents a straight surface which is tangential to the periphery of the carding cylinder at a single point only. By the instant invention, it is possible to quite simply construct a carding surface on a flat which is tangential with the periphery of the carding cylinder at two points. The carding surface is made from a plurality of toothed strips 22 provided with bends 25 at the midpoint, as il- Iustrated in FIGS. 3 and 17. These strips 22 are mounted in a V-shaped groove in a backing piece 76, as illustrated in FIG. 18. Strips 22 can be fastened into groove 75 by any of the means previously shown, such as a glue 77. When placed in V-shaped slot 75, the bottom of the strips conforms to the bottom of the groove and the bend 25 engages the apex of the V- shaped groove 75. Thus, strips 22 are tilted and present on end view, a section that is V-shaped, to match groove 75 (see FIG. 18). FIG. 19 shows in section the arrangement of laterally tilted strips 22. As shown in FIG. 20, the resulting carding surface has two points 78 and 79 tangential with the periphery of carding'cylinder 16, thus providing greater and more effective carding action. Of course, both legs 29 and 30 of strips 22 are mounted at an angle to the direction of fiber flow, as taught above. Thus, this embodiment provides all the previously described advantages of the invention.

FIGS. 21-26 illustrate the elements of a throwaway flat which is manufactured of inexpensive material and which is particularly well adapted for use within the novel concepts of this invention. The basic T-shaped section is shown in FIGS. 21 and 22 and is manufactured of an inexpensive material such as any of the commercially available synthetic plastics. lnstalled on each end of T-shaped section 90 is an end piece 91 which engages the guides in the carding apparatus (not shown); End piece 91 has a slot 96 which receives the stem portion 97 of section 90. End piece 91 should, at least in part, be made of durable material such as metal. Also installed on each end of T-shaped section 90 is a sprocket seat and chain-screw housing 92 which should also be of metal. Housing 92 has a slot 98 which receives stem-portion 97. T-shaped section 90, end piece 91, and housing 92 are attached together by commonly used means such as glue. A slot 94 is provided on the upper surface of T-shaped section 90 for receiving a plurality of toothed strips 22 in any one of the manners previously described. The advantage of this flat resides in the fact that it is designed to take advantage of the use of inexpensive materials, and therefore entire flat can be discarded when the carding teeth become dull or otherwise deteriorate.

The invention set forth herein is not to be considered as limited by the embodiments described. Many additional modifications and other embodiments may become apparent to those skilled in the art, and the scope of the invention is to be limited only by the following claims.

I claim:

l. A carding flat comprising a backing,

and nested together along said backing, each of said strips having a plurality of carding teeth spaced therealong and extending upwardly therefrom,

a rigid plastic material covering said teeth to a predetermined height, said plastic material interconnecting said teeth and defining continuously over said teeth a hard, smooth, flat surface through which only the tips of said teeth protrude.

2. A carding flat according to claim 1 wherein said plastic material is a resinous material.

3. A carding flat according to claim I wherein said plastic material is a polyester resin.

4. A carding flat according to claim 1 wherein said plastic material is an epoxy resin. 

1. A carding flat comprising a backing, a plurality of metallic strips which are laterally bent and nested together along said backing, each of said strips having a plurality of carding teeth spaced therealong and extending upwardly therefrom, a rigid plastic material covering said teeth to a predetermined height, said plastic material interconnecting said teeth and defining continuously over said teeth a hard, smooth, flat surface through which only the tips of said teeth protrude.
 2. A carding flat according to claim 1 wherein said plastic material is a resinous material.
 3. A carding flat according to claim 1 wherein said plastic material is a polyester resin.
 4. A carding flat according to claim 1 wherein said plastic material is an epoxy resin. 